Caster



(NoModeL) S. O. MENDENHALL.

GASTER. No. 314,955. Patented Mar. 31, 1885.

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niture and other PAT NT OFFICE.

STEPHEN O. llIENDENI-IALL, OF RICHMOND, INDIANA.

OASTER.

SPECIFICATION forming part of Letters Patent No.

314,955, dated March 31, 1885.

Application filed September 6, 1984. (No model.)

To all whom it may concern:

Be it known that .1', STEPHEN O. MENDEN- HALL, a citizen of the United States, residing at Richmond, in the county of lVayneand State of Indiana, (present business address Cincinnati, Ohio,) have invented certain new and useful Improvements in Casters for Fur Articles, of which the following is a specification.

The object of the present invention is to provide a cheap, simple, andstrong oscillating two-wheel caster which shall not be subject to the tilting and locking action which is one of the main detrimental features of this class of casters as ordinarily constructed, and which takes place whenever the floor-wheel on one side is forced laterally against a scam in the carpet or other obstruction on the iioor. The reason for such action with the ordinary two-wheel caster is that the point of transmission of force from the furniture stud or pintle-the center of horizontal as well as vertical swiveling motionis placed above the top of the floonwheels, or at least above the axis of said wheels. The leverage thus afforded renders the floonwheel housing liable to tip up with the slightest force, if the outside of the floor-wheel lying on the side of the truck in the direction of motion of the caster be lying against a scam in the carpet, for example. This evil, it is apparent-,will be avoided in degree proportional to the dropping ofthe center of motion of the caster, such dropping of the caster being only limited by the fioorsurface. It said center could be placed so low as to lie in the plane of resistance, it would be impossible to tip the caster by a sidewise movement applied to its spindle; but such plane is generally so nearly coincident with the floor-surface as to render this construction practically impossible.

In practice I find a sufliciently satisfactory result is attained, while economical ends are best subserved, by placing the said center in a plane slightly below the floor-wheel axis. Vithjsuch a construction the motion of the center of oscillation is practically entirely within a horizontal plane, and both floorwheels are kept constantly in contact with the floor. I do not, however, wish to be understood as limiting myself to such a con-.

struction, but leave myself the option of plac- ]ing the center of oscillation at any height above the floor as shall, in any particular form and size of caster in which it is employed, best secure wheels in constant contact with the floor. This principle is not applicable without a clumsy mechanical construction-to two-wheel casters in which the floor-wheels are placed between forks on the housing or saddle, but only to those in which the spindle-connection is made to the center of the floor-wheel axis,between the wheels. I therefore cast the floor-axle in one, with an arm projecting forward horizontally, or nearly so,when the caster is put together. The spindle surrounds this arm in such a manner as to allow vertical oscillation. The advantages of such a coir struction are, first, while the whole is readily bio of being riveted together, there are no rivets employed on that part of the caster lying between the center of oscillation and point of application of the weight of the furniture. It being this portion of the caster which sustains the most strain, many breakages result in the ordinary form of caster from the initial strain put upon the metal by riveting a pin within it.

Second. The easily-broken ears or forks of casters of ordinary form are dispensed with.

In order that my invention may be more fully understood, I will proceed to describe it, with reference to the accompanying drawings, in which- Figure 1 is a perspective view from the rear of my improved caster, showing the employment of a horizontal arm lying in the same plane with the floor-wheel axle. Fig. 2 is a view showing the top in vertical section, part of the spindle broken away to show the oscillating mechanism and one floor-wheel removed. Fig. 3 is a perspective of the spindle and fioorwheel axle. Fig. 4 is a rear View other being removed. Fig. 5 is a view similar to Fig. 2, with the top removed, illustrating the preferred form of caster, in which the center of movement of the caster is placed below the floor-wheel axis.

1 is a stem-caster socket-top bearing antifriction ring 2, and having stud or pin 3 for occupying groove 4 in the spindle 5, the conishowing one floor-wheel in vertical section, the

the end of retaining both made of malleable cast-iron, so as to be cape.

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' cal head 6 of which bears the full weight of the piece of furniture or other article to which the caster is attached. A top similar to the present has been described and claimed in my application filed on the 25th of August, 1884, (Serial No. 141,522,) and, is therefore not here in specially claimed. The spindle 5 is cast with a cylindrical bearing at bottom,which is occupied by the cylindrical arm 7, cast on the floor-wheel axis 8. The casting 8 is preferably made of malleable iron, so that when the arm .7 is inserted in its bearing, and the washer 9 slipped over the neck 10 against a shoulder formed thereon the end of riveted over said washer to retain the spindle. The shoulder on the arm prevents the forming of too tight a joint between the spindle and its bearing due to careless riveting. The making'of the casting 8 of malleable iron also permits the ends of the axlespindles 11 to be riveted over the washers 12 for retaining the floor-wheels 13 in place. The said axle-spindles are also shouldered to keep the washers from being too closely clampedagainst said floor-wheels. A ridge or web, 14, formed on the rear of the spindle 5,increase's the strength thereof, and renders the transmission of strain more direct from the top of the spindle to the floor-wheel axle.

It will be obvious that with a caster constructed as above described it will be practically verv difficult to tip one wheel from the floor should the other strike laterally on an obstruction on the floor. To make protection from such an accident still more complete, however, I may so form the casting 8 as that the horizontal arm 7 will be in a plane below that of the floor-wheel axis, as shown in Fig. 5.

said neck may be It will be observed that between the point of oscillation 7 and the top of the spindle there are no riveted connections, and a fertile source of breakage of the common two-wheel oscillating caster is thus avoided.

Having lowing is what I claim as newtherein and desire to secure by Letters Patent:

1. In an oscillating caster, the combination, with two floor-wheels and a spindle, of a horizontal arm fixed to the floor-wheel axis and lying in a plane below the same, substantially as set forth.

2. In an oscillating caster, in combination with two floor-wheels having a solid axle, and a solid cylindrical arm projecting therefrom. the spindle having corresponding cylindrical bearing, substantially as set forth.

3. In combination with two floor-wheels and thus described my invention,the fol- I a spindle having cylindrical bearing, as shown,

the solid floor-wheel axle made of malleable iron, and having cylindrical arm and floorwheel trunnions cast in one therewith and riveted over at their ends for retaining the spindle and floor-wheels thereon,substantially as shown and described.

4. In combination with a spindle having horizontal cylindrical bearing for a projection on the floor-wheel axis, a furniture socket or top,and horizontal anti-friction wheels or rollers within said top for taking up lateral strain on the spindle, substantially as set forth.

STEPHEN G. MEN DEN HALL. 

